The present disclosure relates to an exchange device controlling one or more optical network units (ONU) for a wavelength division multiplexing (WDM)/time division multiplexing (TDM)-passive optical network (PON).
Generally, in a WDM/TDM-PON, PON branches from a plurality of communication areas are taken as one PON branch based on WDM technology to improve the efficiency of bandwidth allocation for the entire communication area. For example, if an ONU requiring a large bandwidth is present, that ONU is allocated a large bandwidth by dedicating one wavelength to the PON branch that the ONU belongs to. This allocation is carried out by controlling the PON branch in one of the transmission devices that is included in an exchange device. Conversely, if a plurality of PON branches that do not require a large bandwidth are present, the plurality of PON branches are controlled together in one of the transmission devices included in the exchange device. Thus, by collectively controlling PON branches that have a small required bandwidth, the total number of operations in a transmission device is decreased, which allows power consumption to be reduced (e.g., JP 2011-82908A (US2011/085795) and JP 2011-135280A).
One method for realizing such an operation is wavelength routing, which uses a tunable transmission device and an AWG (arrayed waveguide grating). When using such devices, the routing destination of the data can be changed by changing the wavelength setting to the transmission device. Consequently, data can be allocated to the respective PON branches and transmitted with one transmission device by changing the wavelength setting to the transmission device for each piece of data. Namely, a plurality of PON branches can be controlled by one transmission device, thereby enabling lower power consumption.